Re: [PATCH 1/3] ata: sata_dwc_460ex: use "dmas" DT property to find dma channel

[Måns Rullgård]

Julian Margetson <runaway@xxxxxxxx> writes:

> On 12/18/2015 1:18 PM, Måns Rullgård wrote:
>> Julian Margetson <runaway@xxxxxxxx> writes:
>>
>>> On 12/18/2015 8:49 AM, Måns Rullgård wrote:
>>>> Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> writes:
>>>>
>>>>>>> [    5.206125] Unable to handle kernel paging request for data at
>>>>>>> address 0x00000000
>>>>>>> [    5.228546] Faulting instruction address: 0xc043a2c8
>>>>>>> [    5.248577] Vector: 300 (Data Access) at [eddafae0]
>>>>>>> [    5.268658]     pc: c043a2c8: sata_dwc_qc_issue+0xb8/0x204
>>>>>> Well, that's not good.  Can you translate that address to a line of
>>>>>> code?
>>>>> Besides that, can you enable DYNAMIC_DEBUG in the config and append
>>>>> 'dw_dmac_core.dyndbg dw_dmac.dyndbg' to the kernel cmdline?
>>>> Enabling debug messages in the sata_dwc driver might also be informative.
>>>>
>>> Changed the sata-dwc to a module .
>>>
>>> [   18.475140] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL
>>> [   18.535698] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL
>> That's strange.  The only way that can happen is if
>> dmaengine_prep_slave_sg() return NULL, and that really shouldn't be
>> happening.  Did you turn on debug messages in dw_dma?  You can enable
>> some extra debug messages by adding "#define VERBOSE_DEBUG" at the top
>> of drivers/dma/dw/core.c
>>
>
> [   17.526173] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL
> [   17.600124] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL
> [   17.662978] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL

Could you post the entire kernel log?  There might be important
information before the errors start.

-- 
Måns Rullgård
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